I labelled sulci in 40 T1 volumes and have created surface overlays using mri_vol2surf and then registered these to fsaverage using mri_surf2surf. I want to generate a statistical probability map using mri_concat and then mris_fwhm for each sulcus. What is an acceptable FWHM to use? It is the width of a sulcus on a pial surface of an individual brain, i.e. about 2mm? Or on fsaverage, i.e. about 7mm?

Thanks

Trisanna